Dark matter direct search sensitivity of the PandaX-4T experiment

TL;DR

This paper presents a simulation study of the PandaX-4T dark matter detector's background levels and its potential sensitivity to detecting weakly interacting massive particles, aiming to improve dark matter search capabilities.

Contribution

It provides detailed background estimates and sensitivity projections for the PandaX-4T experiment, highlighting its potential to detect extremely rare dark matter interactions.

Findings

Electron recoil background: 4.9x10^{-5} / (kg day keV)

Nuclear recoil background: 2.8x10^{-7} / (kg day keV)

Sensitivity to dark matter-nucleon cross section: 6x10^{-48} cm^{2} at 40 GeV/c^{2}

Abstract

The PandaX-4T experiment, a four-ton scale dark matter direct detection experiment, is being planned at the China Jinping Underground Laboratory. In this paper we present a simulation study of the expected background in this experiment. In a 2.8-ton fiducial mass and the signal region between 1 to 10 keV electron equivalent energy, the total electron recoil background is found to be 4.9x10^{-5} /(kg day keV). The nuclear recoil background in the same region is 2.8x10^{-7}/(kg day keV). With an exposure of 5.6 ton-years, the sensitivity of PandaX-4T could reach a minimum spin-independent dark matter-nucleon cross section of 6x10^{-48} cm^{2} at a dark matter mass of 40 GeV/c^{2}.